Passenger vehicles often include electric batteries for operating features of a vehicle's electrical and drivetrain systems. For example, vehicles commonly include a 12V lead-acid automotive battery configured to supply electric energy to vehicle starter systems (e.g., a starter motor), lighting systems, and/or ignition systems. In electric, fuel cell (“FC”), and/or hybrid vehicles, a high voltage (“HV”) battery system (e.g., a 360V HV battery system) may be used to power electric drivetrain components of the vehicle (e.g., electric drive motors and the like). For example, an HV rechargeable energy storage system (“ESS”) included in a vehicle may be used to power electric drivetrain components of the vehicle.
Information regarding a relationship between state-of-charge (“SOC”) and an open-circuit voltage (“OCV”) of a battery system may be utilized in modeling battery system performance and/or in connection with battery system control and/or management decisions. For example, information regarding energy stored in a battery system included in a vehicle, which may be determined using an SOC-OCV curve associated with the battery system, may be utilized in estimating a range of the vehicle. In some embodiments, various battery system parameter and/or performance information may be determined by a battery state estimation (“BSE”) system associated with the battery system.
The electrical behavior of a battery system may change over time as the battery system ages. For example, a charge capacity of the battery system may decrease and an equilibrium voltage (e.g., an OCV) of the battery system for a given SOC may shift from its value at the beginning-of-life (“BOL”) of the battery system. Certain algorithms used in connection with estimating battery system parameter and/or performance information, however, may not account for such changes and may assume that an OCV/SOC relationship for the battery system is static throughout its life.